1. Technical Field
The present invention relates to an image forming apparatus.
2. Related Art
As an image forming apparatus such as a printer, a facsimile machine, a copier, a plotter, and a multifunction apparatus combining several of the capabilities of the above devices, for example, an inkjet recording apparatus is known that includes a print head to discharge ink droplets and performs printing by discharging droplets onto a recording medium.
Such an image forming apparatus includes a maintenance unit to clean and maintain performance of the recording head. The maintenance unit includes a cap to seal nozzles of the recording head, a suction pump to suck air in the cap, and a wiping member to wipe clean the nozzle surface, such as a wiper or a wiper blade. To drive the cap and the wiper included in the maintenance unit, a drive force of a drive source for a conveyance device to convey a recording medium is transmitted to the maintenance unit.
Conventionally, output power from a plurality of drive sources is transmitted to each of a plurality of driven members, as follows: a first switchover gear driven to rotate based on the output from a first drive source; a second switchover gear driven to rotate based on the output from a second drive source; a plurality of transmission gears disposed in parallel to each other, engageable with either the first switchover gear or the second switchover gear, and to transmit drive force to each of the plurality of driven members; a drive shaft to support the first switchover gear and the second switchover gear to slide in a predetermined direction in which a carriage moves reciprocally; a positioning device to selectively position the first switchover gear and the second switchover gear at any position among a plurality of drive force transmission positions corresponding to the transmission gear to slide the carriage in the predetermined direction n which the carriages moves reciprocally and thereby change a drive force transmission position of the first and second switchover gears; and a biasing member to elastically bias the positioning device along the predetermined direction which the carriage moves reciprocally.
Conceivably, an arrangement is possible in which moving the carriage moves a position of the drive force transmission gear so that a single drive source transmits the drive force to the recording medium conveyance means during image formation and to the maintenance unit during maintenance.
In this case, however, if the drive force can be transmitted to the maintenance unit only when the carriage remains stationary on the maintenance unit, waste liquid attached to the wiper cannot be cleaned by a cleaning member after the head surface has been wiped.
Specifically, because the wiping is performed after the carriage is moved and the nozzle surface is moved relative to the wiper member, the carriage is separated from the maintenance unit after the wiping operation and the driving force cannot be transmitted to the cleaning member.
As described above, moving of the drive force transmission gear alone by the carriage cannot drive the cleaning member of the maintenance unit to clean the wiper member and thus another drive source is required, which complicates the structure and increases the size of the apparatus, resulting in a cost rise.